Ever since the iPhone X was announced, it has consistently been reported that the handset will be in short supply for several months after it’s released. Some iPhone X suppliers are facing yield issues with key components, one of the components is the dot projector for the TrueDepth camera that powers the facial recognition functionality. According to a new report, the suppliers are still facing issues with this component.

The dot projector is the component that projects 30,000 dots on the user’s face which creates a depth map that the Face ID authentication system uses to decide whether or not the handset should be unlocked. It’s also used for the airmoji feature in iMessages.

The Nikkei Asian Review reports today that the iPhone X suppliers have still not been able to work out the issues that are causing yield problems for the 3D sensors. Many reports have actually referred to this issue as the major production bottleneck for iPhone X production.

Yuanti Investment Consulting analyst Jeff Pu predicts that the iPhone X will soon enter mass production and units will start shipping out of China in the third week of this month. However, since this issue has still not been sorted out, he has revised his own 2017 iPhone X shipments prediction down from 40 million units to 36 million.

Apple will start taking pre-orders for the iPhone X on October 27th. It will be released on November 3rd.